▎ 摘　　要

We investigate bending behaviors of graphene nanoribbons (GNRs) induced by surface adsorption of hydrogen atoms or molecules. At low adsorption coverage, it is shown that the chemical adsorption of hydrogen atoms causes a GNR to bend away from the adsorbed atoms while the physical adsorption of hydrogen molecules causes it to bend toward the adsorbed molecules. Interestingly, these trends are reversed at high adsorption coverage. There exists a range of linear responses for both chemical and physical adsorptions, which points to promising applications of GNRs as sensitive chemical-/biosensors. (C) 2011 American Institute of Physics. [doi:10.1063/1.3569589]